Recent scientific research has generated new medications with the potential to improve treatment of alcohol abuse and dependence. However, unless these new medications are accepted by the treatment community, their potential to improve outcomes will not be realized. Clinicians have been slow to adopt naltrexone, recently approved as the first new medication for alcoholism treatment in forty years. This research studies the adoption of naltrexone by alcoholism treatment clinicians in different settings to identify factors that encourage or impede its adoption as an adjunct in treatment. Alcoholism treatment clinicians (both physicians and non-physician clinicians) in three states (Massachusetts, Washington State, and Tennessee) will be surveyed regarding their acceptance of naltrexone as well as other pharmacological therapies in treatment. Multivariate logit analysis will be used to estimate the effect of individual clinician characteristics, characteristics of their treatment settings, and state location on the adoption or non-adoption of naltrexone by clinicians. This will support empirical assessment of differences in adoption of naltrexone by physician and non-physician clinicians, and by those practicing in the public and private sector, in managed care and other settings, and in different state treatment environments. Data on sales of naltrexone provided by the manufacturer will be used to provide background context. Secondary sources will supplement survey data regarding organizations in which clinicians practice and the state treatment environment. As more pharmaceuticals are developed for treatment of alcohol and other addictions, information is needed on barriers to and facilitators of their adoption by clinicians. This research will document and explain patterns of acceptance of such medications to inform strategies for dissemination of future treatment innovations.